TNM staging system

The TNM system has been widely adopted in many areas as a replacement for idiosyncratic disease specific systems. The number of Ts Ns and Ms depend on the tumour/site but in general:


T: Tumour
  • Tx: primary tumour cannot be assessed
  • T0: no evidence of primary tumour
  • Tis: carcinoma in situ
  • T1: site/tumour specific, generally small
  • T2: site/tumour specific
  • T3: site/tumour specific, generally large
  • T4: site/tumour specific but usually refers to direct extension into adjacent organs/tissues.
N: Nodes
  • Nx: nodes cannot be assessed
  • N0: no evidence of nodal involvement
  • N1: site/tumour specific
  • N2: site/tumour specific
  • N3: site/tumour specific
M: Metastases
  • Mx: presence of metastases cannot be assessed
  • M0: no evidence of metastases
  • M1: distant metastases present

Other descriptors

The TNM system has been expanded to include other measures:

  • R: resection status
  • V: vascular invasion


Additional prefixes can be apended to define the TNM stage:

  • c: clinical assessment data
  • p: pathological data
  • y: clinical (yc) or pathological (yp) data following ystemic or radiation therapy be it prior to surgery or as a primary treatment
  • r: clinical or pathological staging at the time of retreatment for recurrence or disease progression
  • a: autopsy data


  • m: multiple primary tumours, e.g. T2(m) or T2(5)

In addition TNMs can be combined into stages I , II , III, IV, e.g. lung cancer staging.

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Article Information

rID: 2140
System: Oncology
Section: Staging
Tag: oncology
Synonyms or Alternate Spellings:
  • TNM staging
  • TNM

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